我就是不知道HILIC柱子能不能用这么多水，所以才来咨询的，以前没有用过~真的不能超过50%？

最好不要超过50%的水，对柱子非常不好。
可以试着改变一下流动相pH值，改变一下化合物的离子状态，但pH不要超过6。
还有你的柱子规格是什么呢？
可以把流速再提高，然后在质谱前面加一个三通分流。

HILIC柱子的水相比例最大不能超过60%,而且强洗和弱洗与反相柱刚好相反,这点要注意.

晕倒啊，不是这样来提前出峰时间的，好好去看看梯度洗脱的定义吧

这也是没有办法的办法，通过改变流动相的比例已经不能让出峰时间提前了~~

不知道你用多长的柱子，有没有短一点的呢？

那也不能这样通过提高流速来改变保留时间啊，完全是瞎搞，你设计具体的洗脱程序吗，贴出来让大家给你分析分析。

应该是使用的时候最好有机相要高的,不然也体现不出hilic柱子在液质联用上的优势!一般是要加易挥发盐的,不然保留时间可能不太稳定.

我在国外网站上查到下面这一段,但是有些怀疑,可能这种类型的是键合氨基的.毕竟HILIC柱子只是一种作用模式,针对具体的柱子还是要仔细研究一下说明书的.

Operating Recommendations for HILIC Separations

Initial Use: When using either column to perform HILIC separations, flush the new column with 30 mL water, and then condition with at least 60 mL of a buffer solution with a salt concentration of 0.2 - 0.4 M and a pH in the range of 3 - 6 (exact figures are not important here). Flush again with another 20 ml water, then equilibrate with 30 ml of the mobile phase before injecting samples. (These volumes relate to 4.6 mm ID columns. For 9.4 mm ID columns, the volumes above should be multiplied by a factor of four).


Routine Use: Filter samples and mobile phases before use. Flush and store HILIC columns in water when not in use. Operation at room temperature is recommended, since elevated temperature shortens column lifetime.

General Mode of Operation: Salt is not required with solutes that are not electrolytes. In the case of electrolytes, use at least 25 mM buffer in the mobile phase. Gradient elution can be accomplished by a decreasing organic gradient (starting from 80-85% acetonitrile for peptides or 95% for phospholipids) or an increasing salt gradient (which typically gives flatter baselines). Solubility of salts can be a problem with mostly organic mobile phases, but sodium perchlorate works well and is transparent at low wavelengths (Fisher sells an HPLC grade). Buffer salts with reasonable solubility in 80% acetonitrile include triethylamine phosphate (TEAP) and sodium methylphosphonate (from methylphosphonic acid). Isocratic retention is typically several times greater with TEA salts than with the corresponding sodium or potassium salt. With 80% acetonitrile, concentrations of 75 mM (pH 5.0) or 100 mM (pH 2.8) TEAP are attainable. Gradient elution in HILIC generally requires one-fifth to one-tenth the concentration of salt required in ion-exchange chromatography.





A stock solution of TEAP can be prepared by making a concentrated aqueous solution of phosphoric acid, adding TEA until the desired pH is attained, then diluting to give a known final concentration (e.g., 2 M in phosphate). Similar methods are used with phosphonate buffers. Prepare stock solutions fresh monthly and store in the refrigerator. For preparation of the mobile phase, add the appropriate amount of stock solution and water to a volumetric flask. Next, add the acetonitrile to a level several mL short of the mark. Mix, then put the flask in a sonication bath for 5 minutes, this degasses and warms the solution. Finally, add acetonitrile to the mark and mix.





Organic solvents such as isopropanol can be used as alternatives to acetonitrile, but higher concentrations are usually required to attain the same degree of retention, and the resulting mobile phases are appreciably more viscous.

HILIC柱子是适合于分析极性大些的物质。但是其效果有多明显可能还是要看具体的物质。不是一概而论。HILIC柱的流动相梯度是要和反相柱相反的。开始时需要使用高有机相，慢慢过渡到水相，水相也不要太高，具体多少不是很清楚，参照楼上版友们的建议！

HILIC柱流动相中水相比例不能超过60%，也只对碱性物质有保留，象楼主的情形，改变梯度是没办法提前出峰时间的，但可以改用甲酸或其他缓冲液来试试。